[R] eliminating control characters from formatted data files

[Murray Cooper]

David,

This may be a case of "If all you have is a hammer, everything looks like a 
nail".
If all you want to do is remove the last line if it contains a CONTROL-Z, 
why
not use something like perl to process the files?

Murray M Cooper, Ph.D.
Richland Statistics
9800 N 24th St
Richland, MI, USA 49083
Mail: richstat at earthlink.net

----- Original Message ----- 
From: "David Epstein" <David.Epstein at warwick.ac.uk>
To: <r-help at r-project.org>
Sent: Thursday, February 05, 2009 4:01 AM
Subject: [R] eliminating control characters from formatted data files


>
> I have a few hundred files of formatted data. Unfortunately most of them 
> end
> with a spurious CONTROL-Z. I want to rewrite the files without the 
> spurious
> character. Here's what I've come up with so far, but my code is unsafe
> because it assumes without justification that the last row of df contains 
> a
> control character (and some NAs to fill up the record).
>
> options(warn=-1) #turn off irritating warning from read.table()
> df<-read.table(file=filename)
> df.new<-df[1:nrow(df)-1,]
> write.table(df.new,file=filename.new, quote=F)
>
> Before defining df.new, I want to check that the last line really does
> contain a control character. I've tried various methods, but none of them
> work.
>
> I have been wondering if I should use a function (scan?) that reads in the
> file line by line and checks each line for control characters, but I don't
> know how to do this either.
>
> Thanks for any help
> David
> -- 
> View this message in context: 
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>
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